1. Field of the Invention
The present invention relates generally to a portable terminal and a data input method therefor, and in particular, to a method and apparatus for receiving data from a virtual input device by detecting and analyzing the motion of a user input means using a two-dimensional image sensor without projecting the virtual input device.
2. Description of the Related Art
Due to the miniaturization of portable terminals, typically an input device for a portable terminal has a limited input capability. For expanded input capability, an external expanded input device is connected to the portable terminal. For example, existing external input devices include the Qwerty keyboard, which is widely used, and a virtual input device.
FIG. 1 illustrates a conventional portable terminal connected to an external input device. Referring to FIG. 1, an external input device 12 is connected to a portable terminal 11 via a communication port, for wired/wireless communications. The user separately carries the external input device 12 and needs a connector 13 for connecting the external input device 12 to the portable terminal 11. Therefore, this type of external input device creates some inconvenience and prevents easy portability.
FIG. 2 illustrates another conventional portable terminal using a virtual input device. Referring to FIG. 2, the image of a virtual input device 22 is projected from a projector 27 of a portable terminal 21. When the user types on the virtual input device 22, sensors 23, 24, and 25 sense the motions of the user's hands 26 and recognize input data. This input method requires the projector 27 and the sensors 23, 24, and 25 for sensing the motion of the user's hands 26 and it is significant how accurately the sensors 23, 24, and 25 sense the hand motions.
A conventional portable terminal that receives data using a virtual input device generally senses hand motions three-dimensionally using a plurality of sensors, as illustrated in FIG. 2. However, the requirement of a projector and a plurality of sensors make the configuration of the portable terminal complicated and thus the portable terminal is not user-friendly. Additionally, the increase of components increases the cost of the device. Further, the use of the virtual input device is restricted depending on the positions of the projector and the sensors.